// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <stddef.h>

#include "testing/gtest/include/gtest/gtest.h"
#include "ui/gfx/utf16_indexing.h"

namespace gfx {

TEST(UTF16IndexingTest, IndexOffsetConversions)
{
    // Valid surrogate pair surrounded by unpaired surrogates
    const base::char16 foo[] = { 0xDC00, 0xD800, 0xD800, 0xDFFF, 0xDFFF, 0xDBFF, 0 };
    const base::string16 s(foo);
    const size_t the_invalid_index = 3;
    for (size_t i = 0; i <= s.length(); ++i)
        EXPECT_EQ(i != the_invalid_index, IsValidCodePointIndex(s, i));
    for (size_t i = 0; i <= s.length(); ++i) {
        for (size_t j = i; j <= s.length(); ++j) {
            ptrdiff_t offset = static_cast<ptrdiff_t>(j - i);
            if (i <= the_invalid_index && j > the_invalid_index)
                --offset;
            EXPECT_EQ(offset, UTF16IndexToOffset(s, i, j));
            EXPECT_EQ(-offset, UTF16IndexToOffset(s, j, i));
            size_t adjusted_j = (j == the_invalid_index) ? j + 1 : j;
            EXPECT_EQ(adjusted_j, UTF16OffsetToIndex(s, i, offset));
            size_t adjusted_i = (i == the_invalid_index) ? i + 1 : i;
            EXPECT_EQ(adjusted_i, UTF16OffsetToIndex(s, j, -offset));
        }
    }
}

} // namespace gfx
